Evaluating Orchard: website upgrade

I am evaluating Orchard as the possible CMS for us. We are also considering Drupal too.

One concern about Drupal is that with each major release such as from 6 to 7, upgrading a website is impossible without significant modification, and sometimes the upgrade needs a complete website rewrite.

I really need the objective input about the system design philosophy/architecture as well as actual upgrade experience from Orchard experts and users regarding upgrading an Orchard website to a major release as well as a minor release.

In my experience, I never had to rewrite an application in order to upgrade to the next release. Especially with the upgrade module that comes with each version. Sure, sometimes there's a bug and one needs to go into code or database and fix a little,
but nothing too disturbing. I heard a guy telling a story he was able to upgrade a 1.0 Orchard site all the way up to 1.6.1 without even dropping so much as a sweat!

That being said, I have no idea what will happen when we get to 2.0, but as far as I know the philosophy has always been to provide upgrade paths.

Minor release updates are usually not a problem. There is always a module (called
Upgrade) that performs all updates, if necessary.
We haven't had a new major release yet, so in this case I can't tell.

About the upgrade itself - from my experience the most problematic part is not Orchard core, but rather the modules you are using (either yours or third-party). And it's the case for all CMSes and modular frameworks out there. We can make sure the core features
(all that comes in a package) are upgraded seamlessly, but keeping up with updates is the modules' authors responsibility. So it all depends - the more custom and complex modules you're using, the bigger chance that you'll need to modify something manually.

Personally, I never had to rewrite the whole website ever. Just a few updates here and there whenever there was a breaking change. I always keep, and advise you to do the same, a separate code branch in my private fork(s) synced with latest Orchard 1.x branch.
This way you can handle possible upgrade problems one by one, very early, and be prepared when the new release comes in offically.

Speaking of architecture - it's great and one of the reasons I picked up Orchard. The second being that it's ASP.NET MVC. Core design concepts in Orchard are very similar to Drupal's. We also took a lot of feature ideas specifically from Drupal.
Going Orchard or Drupal is in your case also a choice between .NET and PHP. So if you're planning some custom development you need to take this into account.

Sorry, I couldn't say, but not this year for sure. The next release will be 1.7 (this week or the next), then 1.7.1 (couple or more weeks later), then perhaps 1.7.2, etc. and eventually 1.8. Bottom line: we don't have a roadmap. After each release, we
discuss what we want next. You can try and influence us if you like during our weekly developers meeting via
http://orchardproject.net/meeting.

Bottom line: we don't have a roadmap. After each release, we discuss what we want next. You can try and influence us if you like during our weekly developers meeting via
http://orchardproject.net/meeting.

+1. Orchard is a community-based project. If there is a big desire for a certain feature from the community - we'll add it. Panta rhei, so to speak:)